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							|  |  |  | id: 5900f4751000cf542c50ff87 | 
					
						
							|  |  |  | challengeType: 5 | 
					
						
							|  |  |  | title: 'Problem 264: Triangle Centres' | 
					
						
							|  |  |  | --- | 
					
						
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							|  |  |  | ## Description
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							|  |  |  | <section id='description'> | 
					
						
							|  |  |  | Consider all the triangles having: | 
					
						
							|  |  |  | All their vertices on lattice points. | 
					
						
							|  |  |  | Circumcentre at the origin O. | 
					
						
							|  |  |  | Orthocentre at the point H(5, 0). | 
					
						
							|  |  |  | There are nine such triangles having a perimeter ≤ 50. | 
					
						
							|  |  |  | Listed and shown in ascending order of their perimeter, they are: | 
					
						
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							|  |  |  | A(-4, 3), B(5, 0), C(4, -3) | 
					
						
							|  |  |  | A(4, 3), B(5, 0), C(-4, -3) | 
					
						
							|  |  |  | A(-3, 4), B(5, 0), C(3, -4) | 
					
						
							|  |  |  | A(3, 4), B(5, 0), C(-3, -4) | 
					
						
							|  |  |  | A(0, 5), B(5, 0), C(0, -5) | 
					
						
							|  |  |  | A(1, 8), B(8, -1), C(-4, -7) | 
					
						
							|  |  |  | A(8, 1), B(1, -8), C(-4, 7) | 
					
						
							|  |  |  | A(2, 9), B(9, -2), C(-6, -7) | 
					
						
							|  |  |  | A(9, 2), B(2, -9), C(-6, 7) | 
					
						
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							|  |  |  | The sum of their perimeters, rounded to four decimal places, is 291.0089. | 
					
						
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							|  |  |  | Find all such triangles with a perimeter ≤ 105. | 
					
						
							|  |  |  | Enter as your answer the sum of their perimeters rounded to four decimal places. | 
					
						
							|  |  |  | </section> | 
					
						
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							|  |  |  | ## Instructions
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							|  |  |  | <section id='instructions'> | 
					
						
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							|  |  |  | </section> | 
					
						
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							|  |  |  | ## Tests
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							|  |  |  | <section id='tests'> | 
					
						
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							|  |  |  | ```yml | 
					
						
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										 |  |  | tests: | 
					
						
							|  |  |  |   - text: <code>euler264()</code> should return 2816417.1055. | 
					
						
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										 |  |  |     testString: assert.strictEqual(euler264(), 2816417.1055, '<code>euler264()</code> should return 2816417.1055.'); | 
					
						
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							|  |  |  | ``` | 
					
						
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							|  |  |  | </section> | 
					
						
							|  |  |  | 
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							|  |  |  | ## Challenge Seed
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							|  |  |  | <section id='challengeSeed'> | 
					
						
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							|  |  |  | <div id='js-seed'> | 
					
						
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							|  |  |  | ```js | 
					
						
							|  |  |  | function euler264() { | 
					
						
							|  |  |  |   // Good luck! | 
					
						
							|  |  |  |   return true; | 
					
						
							|  |  |  | } | 
					
						
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							|  |  |  | euler264(); | 
					
						
							|  |  |  | ``` | 
					
						
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							|  |  |  | </div> | 
					
						
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							|  |  |  | </section> | 
					
						
							|  |  |  | 
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							|  |  |  | ## Solution
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							|  |  |  | <section id='solution'> | 
					
						
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							|  |  |  | ```js | 
					
						
							|  |  |  | // solution required | 
					
						
							|  |  |  | ``` | 
					
						
							|  |  |  | </section> |